Welding device



Oct. 19, 1943.

W. S. SOUTHWICK WELDING DEVICE Filed June 26, 1942 b 39 flito rney Pateted Oct. 19, 1943 UNITED, STATES PATENT OFFICE WELDING nrzvros WilliamSayles 'Southwick, East Lynn, Mus, assignor to Thomson-Gibb ElectricWelding Company, Lynn, Mass, a corporation of Massachusctts dpplicationJune 26, 1942, Serial No. 448,548

5 Claims.

This invention relates to electric welding devices and particularly to adevice for welding together -two crossing wires of a preformed wirefabric.

After a wire fabric has been manufactured it is frequently necessary toweld together an occasional longitudinal (sh-and") wire and a transverse(stay) wire at their mutual point of crossing, as, for example, wherethe machine which made the fabric skipped a crossing which it wassupposed to weld, leaving it unwelded. Such an unwelded crossingconstitutes an imperfection and is desirably welded in an ensuingoperation called skip welding. Skip welding involves positioning theunwelded wires at their crossing between a pair of electrodes atopposite sides of the fabric, pressing the wires together between theelectrodes and passing a welding current from one electrode through thecrossed wires at the crossing to the other electrode for a sufllcientinterval to effect the weld.

An object of this invention is to provide a novel welding device,suitable for skip welding apreformed fabric, in which one of theelectrodes of the pair is adapted to be extended through a preformedfabric, even of small'mesh. For that purpose, the preferred embodimentof my device has a lower electrode constructed of a pair of separableparts which split upon one of the two wires forming the crossing, topass through seperate meshes of the fabric on opposite sides of the wireand come together on the far side of the fabric. This novel electrodecl1= struction enables use of the device for welding crossings of afabric having a mesh too small to be penetrated by the conventionedelectrode and yet affords continuous support for the lower wire of thepair, beneath and on both sides of the crossing.

By this construction the lower electrode, composed of two parts, has atotal cross section which may be greater than the mesh of the fabricwhich it penetrates so that its current carrying capacity is very muchlarger than the conventional electrode.

In the drawing:

Fig. l is a front elevation view of my device partly in section;

Fig. 2 is a side elevation view'thereof;

Fig. 3 is a perspective view of the lower electrode:

Fig. 4 is a vertical section on the line 4-4 of Fig. 5; and 1;,

Fig. 5 is a side elevation view of the electrodes in welding position.

A typical preformed wire fabric (Fig. 3) on which my novel device isadapted to perform skip welding operations is composed of strand wires,of which three are shown at 5a, 5b and 5c, and stay wires, of which twoare shown at la and lb. In such a fabric my device will weld, forexample, the strand wire 5b to the stay wire la which it is assumed werenot welded together, as they should have been, when the fabric was made.The spacing between the center lines of adjacent strand wires oradjacent stay wires may be as small as one-half inch, thus presentingmeshes, as indicated at to and 9b, of an area restricted to somewhatless than one-half inch square.

The device illustrated (Figs. 4 and 5) has a lower electrode, showngenerally at IU, adapted to be inserted through the fabric to support,on

the grooved shoulder ii, the stay wire 1a to be welded, and an upperelectrode l2 adapted to be lowered and pressed down on the strand wire5b where it crosses the stay wire 'ia to effect the weld at thecrossing.

The lower electrode I0 is formed of two jawlike parts Ma and lb (Fig. 3)which are movable relative to each other and have opposed abutting facesX and Y. The part Ilia, integral with block W2, is fixed and part illbis pivotally mounted on stud shaft it, carried by block )2, and springpressed toward part Ina by a spring 20 (Fig. l) seated in a recess 28formed in 9. lug 30 projecting from the frame of the device and in alower recess 22 formed in an arm 24 projecting laterally from the partillb. To extend the lower electrode it) through the fabric, theelectrode is rested on the fabric, which is supported from beneath, withstrand wire 5b received in the notch i?) (Fig. 4) formed between partsMia and lb of the electrode. The device is then pressed against thefabric so that strand wire 51; is forced between parts iiia and iii?) tospread them apart and the device is moved downwardly until groovedshoulder H is lower than the stay wire 1a which it is to support, whenstrand wire 5b is received within complementary recesses iii in partsIlla and lb, allowing the parts to close together on the opposite sideof the fabric. The device is then moved forwardly and upwardly to placethe stay wire la in the groove of the shoulder Ii.

The upper electrode i2 slides vertically in a, vshaped recess 40 (Fig.3) formed in the front faces of the parts Ilia, lb and the electrode I2is V-shaped conformingly. Its lower wire-engaging end is notched at 42(Fig. 4) to insure good electrical contact with the strand wire 5b.

' Electrode l2 (Fig. 1) is secured to a plate 46 by bolts 44 passingthrough elongated slots as (Fig. 2) in the electrode and screw threadedinto the plate. The plate is integral with piece 48- which is L-shaped,as seen in Fig. 2, and to the, back of which is bolted the end of a lowresistance flexible conductor 50 leading from the secondary of astep-down transformer, designated generally at 52. To reciprocate theupper electrode I2 vertically the angle piece 48 is bolted at I I5 tothe base 54 of a slide 56. The slide is electrically insulated from thepiece 48 by insulation I I6 interposed between them and by insulatedbushings IIBa surrounding bolts H5. Slide 56 is received in a slideway58 and is urged downwardly by compression spring 60 extending between aweb 02 formed in the slide and a seat 04 carried by the end of a bolt 66screw threaded through a cap 88 fixed to the frame. By turning bolt 66the pressure with which spring 60 urges electrode I2 against the wirecan be adjusted in an apparent manner.

The electrode I2 is held in raised position by means of a manuallyoperable lever I2 mounted on stud I5 screw threaded into the web 62 andhaving acam I4 which abuts a hardened metal insert 76 secured to theframeand therefore fixed in position. The cam I4 has a lobe I8 and a lowportion 80. When lever I2 is in the position shown in Fig. 2 with thelobe I8 abutting plate I6 the electrode is held in elevated position. Asthe handle is swung counterclockwise spring 60 moves electrode I2 towardthe fabric, which movement continues until the notched end 42 of theelectrode abuts wire 5b To insure that the electrode is pressed againstthe wire with the' full force of spring 60 the portion 80 of the cam islow enough to avoid touching plate I6 in welding.

The secondary of the transformer is also connected to the lowerelectrode by another low resistance conductor 84 bolted to a plate 85whi h is in turn bolted to the frame of the machine by bolts 90. Theplate is insulated from the frame by insulation 94 and by insulatedbushings 04a surrounding the bolts 90. Plate 88 extends downwardly toform a block I00, which has an indenture IOI with which the portion I02aof block I02 carrying the lower electrode I0 is adapted to dovetail. Theportion I02b of block I02 dove tails with a securing plate I I0 boltedonto the block I00.

In this manner the block I02 is securely mounted and electricallyconnected to the conductor 84 by connections insulated from the frame ofthe machine.

The primary of the transformer 52 is supplied with current from asource, not shown, by leads 'I I2 passing through a timer ofconventional type for automatically timing the flow of welding current.A push button 2I6 closes the primary circuit and starts the flow of thecurrent.

When using the device, it is preferably suspended from an overheadcarrier which takes the weight of the device but allows it to be movedvertically and horizontally. The fabric is supported in a generallyhorizontal position. When a skip weld is to be made the lower electrodeis inserted through the fabric in the manner above described and afterthe stay wire Ia has been placed on the grooved shoulder II forming theelectrically contacting surface of the lower electrode, the upperelectrode I2 is pressed on the crossing strand wire b by the operatorrotating lever I2 to its counterclockwise position, as abovedescribed.The push button 2 I 6 is then depressed and the weld made. Thereafterthe upper electrode I2 is elevatedand the lower electrode withdrawn fromthe fabric by first moving the device to remove wireeIa from groovedshoulder II and then lifting the device to force the wire 5b into notchI! (Fig. 4) to separate the parts I0a and I0!) as the device is lifted.

I claim:

l. In-a device for welding, at their crossing, a v

strand and a stay wire of a preformed metal fabric, the combination ofan electrode formed of separable parts adapted to be moved apart toreceive one wire of the pair between them to trically conducting pathfrom one electrode to the other through both wires at their crossing.

2. In a device for welding, at their crossing, a strand and a stay wireof a preformed metal fabric, the combination of .an electrode formed ofseparable parts, a spring pressing said parts together and permittingthem to be spread apart by forcing one wire of the pair between them toextend said electrode through the fabric, a recess between said parts inwhich said wire is received to permit closure together of the parts jextended through the fabric, a shoulder on said electrode to support theother wire of said pair at said crossing, and a complementary electrodeadapted to be moved into contact with the first wire of the pair at saidcrossing to form a closed electrically conducting path from oneelectrode to the other through both wires at their crossing.

3. In a device for welding, at their crossing, a strand and a stay wireof a, preformed metal fabric, the combination of an electrode formed ofseparable parts spring pressed together and adapted to be spread apartby forcing one wire of the pair between them to extend said electrodethrough the fabric, a recess between said parts in which said wire isreceived to permit closure or the parts together below said wire, acontinuous shoulder on said electrode composed of aligned portionsextending along both of said separable parts to support the other wireof said pair beneath and on both sides of said crossing, and acomplementary electrode adapted to be moved into contact with the firstwire of the pair at said crossing to form a closed electricallyconducting path from on electrode to the other through both wires attheir crossing.

4. In a device for welding, at their crossing, a strand and a stay wireof a preformed metal fabric, the combination of an electrode formed ofseparable parts having opposed faces adapted to abut each other, thesaid parts being spring pressed to contact each other at said faces andbeing adapted to be spread apart by forcing one wire of the pair betweenthem, a recess between said parts adapted to receive said wire to permitclosure of the parts together below said wire, a shoulder on saidelectrode having aligned portions extending along both of said parts ina direction substantially normal to the plane of said abutting faces toafford support for the other wire of said pair beneath and on both sidesof said crossing, a pair of notches formed in said separable. parts, onedisposed beneath said contacting faces into which said first wire may beV forced to wedse the faces apart in extending the electrode through thefabric, and the other disposed above said faces and communicating withsaid recess into which said first wire is forced to spread said facesapart in withdrawing the elec trode fromthe fabric, and a complementaryelectrode adapted to be moved into contact with said first wire at saidcrossing to form a closed electrically conducting path from oneelectrode to the other through both wires at their crossing.

5. In a device for welding, at their crossing, a strand and a stay wireof a preformed metal fabric, the combination of an electrode formed 0ducting path from one electrode to the other through both wires at theircrossing.

wnimu SAYLES sou'rnwrcx.

